The present invention generally relates to cases for disc-shaped recording mediums, and more particularly to a case comprising a jacket for accommodating a disc-shaped recording medium and a lid plate for closing an opening of the jacket, which, by cooperation with a disc-shaped recording medium reproducing apparatus having means for enlarging the jacket opening and means for clamping the peripheral part of the disc-shaped recording medium, is capable of placing the recording medium at a reproducing and playing position within the reproducing apparatus by inserting the jacket having the recording medium incased or accommodated therein and closed by the lid plate within the reproducing apparatus, and by inserting the empty jacket once again within the reproducing apparatus, capable of accommodating the recording medium inside the jacket to allow the case to be once again taken out outside the reproducing apparatus.
Conventionally, cases accommodating a disc-shaped recording medium (hereinafter simply referred to as a disc) such as a video disc recorded with video signals, and an audio disc recorded with pulse code modulated (PCM) audio signals, have been proposed. In this type of disc cases, a disc remains at a predetermined position within a reproducing apparatus by performing an operation in which a disc case having the disc accommodated therein is inserted within the reproducing apparatus and then pulled out from the reproducing apparatus, and by inserting the empty disc case into the reproducing apparatus, the disc within the reproducing apparatus is incased inside the disc case, to be obtained outside the reproducing apparatus.
The above conventional type of a disc case comprises a rigid jacket for accommodating a disc, and a tray having a front part which is engaged by engaging means upon complete insertion of the disc case within the reproducing apparatus and an annular or ring portion fixed to the front part for encircling the outer periphery of the disc. When this disc case is inserted within the reproducing apparatus to a predetermined position, the engaging means of the reproducing apparatus engages to and holds onto the front part of the tray. Hence, when the jacket is pulled out from within the reproducing apparatus, the disc is held by the annular portion of the tray and relatively slipped out from the jacket at the above predetermined position, and the outer peripheral edge part of the disc rests on and is supported by a supporting mechanism within the reproducing apparatus. Then, a turntable relatively rises within the inner side of the supporting mechanism, and the disc is placed onto and is unitarily rotated with the turntable, to perform the reproduction. After completion of the reproduction, when the empty jacket is inserted into the reproducing apparatus, the disc is relatively inserted into the jacket together with the annular portion of the tray, and the engagement of the engaging means is released. Accordingly, when the jacket is pulled out from the reproducing apparatus, the disc and the tray is obtained outside the reproducing apparatus together with the jacket in a state in which the disc and the tray is incased inside the jacket.
Thus, in the above conventional disc case, the peripheral side surface of the disc is held by the engaged annular portion of the tray and the disc remains within the reproducing apparatus upon pulling of the jacket outside the reproducing apparatus. Accordingly, a supporting mechanism which is placed with the remaining disc thereon and supports the outer peripheral edge part of the disc, is provided in the reproducing apparatus. Hence, the turntable must be constructed so as to relatively move up-and-down within the inner side of the supporting mechanism. This means that the diameter of the turntable must be smaller than the diameter of the disc, and the outer peripheral edge part of the turntable thus makes contact with and supports the disc at the signal recording surface which is to the inner side of the outer peripheral edge part of the lower disc surface. Therefore, scratches are easily made on the signal recording surface part of the disc which is supported by the turntable, and especially when starting the rotation of the turntable, suffers a disadvantage in that scratches are more easily made in this case due to a force acting in a direction so as to rub the disc. Accordingly, when the disc is used many times, fine reproduction cannot be obtained due to the above scratches formed on the signal recording surface of the disc.
Furthermore, the above tray comprises the annular portion for encircling the outer peripheral surface of the disc, and thus suffers disadvantages in that the construction of the disc case is complex, the manufacturing of the disc case is troublesome, and the disc case requires a large amount of material and cannot be manufactured at low cost.
Moreover, upon reproduction, when a reproducing transducer of the reproducing apparatus moves to the position of the signal recording surface on the disc surface, the reproducing transducer must traverse over the annular portion of the tray. This traversign movement accordingly leads to a disadvantage in that the reproducing transducer moving mechanism must be designed so that the reproducing transducer does not collide with the annular portion, and the construction of the mechanism thus becomes complex.
In addition, the conventional disc case suffered a disadvantage in that, when the disc is relatively pulled out from the jacket by the tray upon insertion and then pulling out of the jacket from within the reproducing apparatus, or when the disc is relatively inserted into the jacket by the tray upon insertion of the empty jacket and then pulling out of the jacket, the jacket rubs against the disc and scratches are easily introduced.